Managing cache backup and restore

Abstract

A method is used for managing cache backup and restore. I/O operations are quiesced at a cache module. A first snapshot of a storage object and a second snapshot of an SSD cache object are taken. The I/O operations at the cache module are unquiesced. A single backup image comprising the first snapshot and the second snapshot is created.

What is claimed is: 
     
       1. A method for use in managing cache backup and restore, the method comprising:
 quiescing I/O operations at a cache module; 
 taking a first snapshot of a storage object and a second snapshot of an SSD cache object, wherein the SSD cache object includes dirty data; 
 unquiescing I/O operations at the cache module; and 
 creating a single backup image comprising the first snapshot and the second snapshot, wherein the single backup image includes a backup header, one or more storage object data blocks, a dirty region logging (DRL) metadata block, and a cache superblock, and wherein a memory area occupied by the single backup image is determined by the equation:
   backup image size=sizeof(storage object)+(2*backupheadersize)+sizeof(superblock, DRL metadata blocks). 
 
 
     
     
       2. The method of  claim 1 , further comprising:
 reading data from the single backup image; and 
 restoring the storage object and SSD cache object from the single backup image. 
 
     
     
       3. The method of  claim 2 , further including mapping restored storage objects and SSD cache object. 
     
     
       4. The method of  claim 1 , wherein the first and second snapshots are point in time snapshots. 
     
     
       5. The method of  claim 1 , wherein the storage object includes at least one of a file, block, or logical unit (LU). 
     
     
       6. The method of  claim 1 , wherein quiescing I/O operations at the cache module includes redirecting I/O to the storage object. 
     
     
       7. A system for use in managing cache backup and restore, the system comprising:
 first logic configured to quiesce I/O operations at a cache module; 
 second logic configured to take a first snapshot of a storage object and a second snapshot of an SSD cache object; 
 third logic configured to unquiesce I/O operations at the cache module; and 
 fourth logic configured to create a single backup image comprising the first snapshot and the second snapshot, wherein the single backup image includes a backup header, one or more storage object data blocks, a dirty region logging (DRL) metadata block, and a cache superblock, and wherein a memory area occupied by the single backup image is determined by the equation:
   backup image size=sizeof(storage object)+(2*backupheadersize)+sizeof(superblock, DRL metadata blocks). 
 
 
     
     
       8. The system of  claim 7 , further comprising:
 fifth logic configured to read data from the single backup image; and 
 sixth logic configured to restore the storage object and the SSD cache object from the single backup image. 
 
     
     
       9. The system of  claim 8 , further including mapping restored storage objects and SSD cache object. 
     
     
       10. The system of  claim 7 , wherein the first and second snapshots are point in time snapshots. 
     
     
       11. The system of  claim 7 , wherein the storage object includes at least one of a file, block, or logical unit (LU). 
     
     
       12. The system of  claim 7 , wherein quiescing I/O operations at the cache module includes redirecting I/O to the storage object. 
     
     
       13. A computer program product for use in managing cache backup and restore comprising:
 a non-transitory computer readable medium encoded with computer executable program code, the code configured to enable the execution of: 
 quiescing I/O operations at a cache module; 
 taking a first snapshot of a storage object and a second snapshot of an SSD cache object wherein the SSD cache object includes dirty data; 
 unquiescing I/O operations at the cache module; and 
 creating a single backup image comprising the first snapshot and the second snapshot, wherein the single backup image includes a backup header, one or more storage object data blocks, a dirty region logging (DRL) metadata block, and a cache superblock, and wherein a memory area occupied by the single backup image is determined by the equation:
   backup image size=sizeof(storage object)+(2*backupheadersize)+sizeof(superblock, DRL metadata blocks). 
 
 
     
     
       14. The computer program product of  claim 13 , the code further configured to enable the execution of:
 reading data from the single backup image; and 
 restoring the storage object and SSD cache object from the single backup image. 
 
     
     
       15. A method for use in managing cache backup and restore, the method comprising:
 quiescing I/O operations at a cache module; 
 taking a first snapshot of a storage object and a second snapshot of an SSD cache object, wherein the SSD cache object includes dirty data; 
 unquiescing I/O operations at the cache module; and 
 creating a single backup image comprising the first snapshot and the second snapshot, wherein a memory area occupied by the single backup image is determined by the equation:
   backup image size=sizeof(storage object)+(2*backupheadersize)+sizeof(SSD dirty blocks)+sizeof(superblock, DRL metadata blocks). 
 
 
     
     
       16. A system for use in managing cache backup and restore, the system comprising:
 first logic configured to quiesce I/O operations at a cache module; 
 second logic configured to take a first snapshot of a storage object and a second snapshot of an SSD cache object; 
 third logic configured to unquiesce I/O operations at the cache module; and 
 fourth logic configured to create a single backup image comprising the first snapshot and the second snapshot, wherein a memory area occupied by the single backup image is determined by the equation:
   backup image size=sizeof(storage object)+(2*backupheadersize)+sizeof(SSD dirty blocks)+sizeof(superblock, DRL metadata blocks). 
 
 
     
     
       17. A computer program product for use in managing cache backup and restore comprising:
 a non-transitory computer readable medium encoded with computer executable program code, the code configured to enable the execution of: 
 quiescing I/O operations at a cache module; 
 taking a first snapshot of a storage object and a second snapshot of an SSD cache object wherein the SSD cache object includes dirty data; 
 unquiescing I/O operations at the cache module; and 
 creating a single backup image comprising the first snapshot and the second snapshot, wherein a memory area occupied by the single backup image is determined by the equation:
   backup image size=sizeof(storage object)+(2*backupheadersize)+sizeof(superblock, DRL metadata blocks).